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Wed, 11 Nov 2026 15:06:55 +0000 (UTC) Received: from onestero-thinkpadp1gen7.tpbc.csb (headnet04.pony-001.prod.iad2.dc.redhat.com [10.2.32.116]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id CED3330000E8; Wed, 11 Nov 2026 15:06:51 +0000 (UTC) Received: by onestero-thinkpadp1gen7.tpbc.csb (nbSMTP-1.00) for uid 13628 oleg@redhat.com; Wed, 11 Nov 2026 16:06:55 +0100 (CET) Date: Wed, 11 Nov 2026 16:06:50 +0100 From: Oleg Nesterov To: Rosen Penev Cc: Masami Hiramatsu , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , James Clark , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Subject: Re: [PATCH v2] uprobes: Use flexible array for xol_area bitmap Message-ID: References: <20261111022605.66010-1-rosenp@gmail.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261111022605.66010-1-rosenp@gmail.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 On 11/10, Rosen Penev wrote: > > --- a/kernel/events/uprobes.c > +++ b/kernel/events/uprobes.c > @@ -108,7 +108,6 @@ static LIST_HEAD(delayed_uprobe_list); > */ > struct xol_area { > wait_queue_head_t wq; /* if all slots are busy */ > - unsigned long *bitmap; /* 0 = free slot */ > > struct page *page; > /* > @@ -117,6 +116,7 @@ struct xol_area { > * the vma go away, and we must handle that reasonably gracefully. > */ > unsigned long vaddr; /* Page(s) of instruction slots */ > + unsigned long bitmap[]; /* 0 = free slot */ I agree with Peter, you can just use unsigned long bitmap[BITS_TO_LONGS(UINSNS_PER_PAGE)]; Oleg.